This invention relates to a rifle magazine and more particularly to a magazine having improved capacity for holding and dispensing cartridges.
While the following discussion talks in terms of a rifle magazine, it is to be understood that such is merely for the sake of convenience and that the application of the magazine is also contemplated for hand guns using cartridge magazines as well. Rifles, and especially automatic and semi-automatic rifles, typically use a cartridge magazine which is removably located to the rear of and just below the rifle chamber entrance. The cartridge magazines used with these semi-automatic rifles may have a capacity of five or six cartridges. Examples of patents showing rifles including cartridge magazines are: U.S. Pat. Nos. 439,833 and 462,298 to Bruce; 506,322 to Lee; and 3,039,221 to Musgrave. In some cases, cartridge magazines of greater length are used to increase capacity. These longer magazines or clips have been a response to the desirable purpose of providing greater capacity in order to enable the rifle to fire an even greater number of rounds before reloading. An example of this type of magazine is shown in U.S. Pat. No. 2,081,235 to Hillyard. With automatic rifles, of course, the number of rounds fired for a given unit of time can be quite large and a single long burst can easily empty a cartridge magazine of even fifteen-round capacity. A practical limit is soon reached when merely adding length to a cartridge magazine in an attempt to solve the capacity problem, since a very long length projecting downwardly tends to make the rifle unwieldy. Also, ground interference is encountered when the rifle is fired from a prone position. Other problems in the area of design are also encountered, since springs within the magazines are used to advance the cartridges by elevating a follower and very long springs cause loading difficulties.
For example, the cartridge spring force is typically proportional to the distance traveled. Thus, a maximum of force is generated when the magazine is fully loaded and the spring is fully compressed. As the cartridges are used up during firing, the spring advancing a cartridge follower extends and the force decreases. A minimum of force is generated when the last cartridge has left the magazine and the magazine spring and follower have reached their limit of travel.
Due to the rifle bolt's advancing of the chambering cartridge over the uppermost cartridge in the magazine, the bolt's motion is somewhat inhibited by the friction generated by sliding contact between the bolt and the uppermost cartridge. The variable force engendered by the magazine spring causes the bolt to chamber the cartridges at an increasing rate of speed as the cartridges are used up. The final round is chambered with a maximum speed. This action is disadvantageous in that the variable cyclic rate thus produced gives rise to burst fire inaccuracy when in full automatic operation.